Preheat oven to 375ºF.
Heat a heavy-bottomed pot over medium-high heat, and brown the sausage, using a wooden spoon to break up any large clumps.
While the sausage is cooking, cut the peppers in half and remove all seeds and ribs, and reserve.
When the sausage is browned, add the shallot, garlic, mushrooms, fennel, and sauté until just tender.
Add the rice and sauté until it begins to turn translucent, stirring constantly.
Deglaze the pan with the wine and add about a cup of the warm stock to the pan, stirring constantly.
As the rice absorbs most of the stock, add more stock, a cup at a time, stirring constantly.
When the rice is al dente, remove from the heat, add half of the basil, half of the parmesan, and all of the butter, and stir until the butter is fully incorporated.
Place the peppers in a glass baking dish and fill the peppers with the risotto.
Combine the breadcrumbs, remaining parmesan, remaining basil, parsley, and extra virgin olive oil.
Top the peppers with the breadcrumb mixture and bake uncovered until the peppers are just tender and breadcrumb mixture is golden brown, about 20-25 minutes.